Evaluation of corrosion on plasma sprayed and anodized titanium implants,both with and without bone cement

The corrosion behavior of titanium with vacuum plasma sprayed titanium coatings and with anodized surfaces, both with and without polymeric bone cement were evaluated. Electrochemical extraction tests were carried out with subsequent analysis of the electrolyte by ICP-MS in order to verify our hypothesis of the ionic permeability of the polymer cement. The complexity of the situation resides in the existence of two interfaces: electrolyte-polymer and polymer-metal. The surface preparation (treatment of the surface) plays an important role in the corrosion resistance of titanium. The electrochemical magnitudes that were examined reveal that the plasma spray surfaces have the lowest corrosion resistance. The cement, in spite of having reduced electrical conductivity in comparison to metal, is an ionic transporter, and therefore capable of participating in the corrosion process. In the present study, we observed in fact crevice corrosion at the metal-cement interface. In the case of plasma spray surfaces, a process of diffusion of titanium particles in the electrolyte could accompany the crevice corrosion. In this study, we have shown that there is a corrosion process at the surface of the titanium through the cement which has as a consequence on the one hand the formation of titanium cations and on the other hand the growth of a passive layer on the titanium. In conclusion, we identified two principal factors that influence the corrosion process: [1] the type of surface treatment for the titanium, and [2] the ionic conductivity of the cement. There is indeed ionic transport through the cement; as evidenced by the presence of titanium in the electrolyte solution (ICP-MS analysis) and chloride at the surface of the titanium sample (EDX analysis).We show that the polymer cement is an ionic conductor and participates in the corrosion of the embedded titanium. We cannot deduce from our results, however, whether the polymer itself possesses corrosive properties. Long-term experiments will be necessary to study the degradation behavior of the polymer cement.     

Difficulties with the follow-up of a cohort of very preterm infants: The EPIPAGE Paris-Petite-Couronne population]

OBJECTIVES: To describe the characteristics of the children of parents who did not respond to a follow-up questionnaire in a cohort of very preterm infants (EPIPAGE study) and to explore the reasons why they did not complete the questionnaires. METHODS: The non-respondents (N = 176) were the parents who did not return the questionnaires at 1 and 2 years. Contacts were organised by telephone calls and at home visits. RESULTS: The families of the non-respondents presented more socioeconomic difficulties and their children were born more preterm than those followed up without difficulties. The efforts made to contact the non-respondents revealed that their families were often confronted with major adverse socioeconomic difficulties, had severe illnesses and psychological troubles. Half of the children of the non-respondents were finally examined at the 5-year assessment. They showed lower performances at the cognitive development test and a poorer health status than the children of the respondents. CONCLUSION: When the follow-up does not include the initial population in its totality, the socioeconomic difficulties are underestimated and probably also the rate of sequelae associated with very preterm delivery.     

Interstitial lung disease in polymyositis and dermatomyositis

OBJECTIVES: To assess prevalence, characteristics, and long-term outcome of interstitial lung disease (ILD) in polymyositis (PM) and dermatomyositis (DM). To determine predictive variables of ILD course in PM/DM, and to define both clinical and biochemical features associated with ILD onset in PM/DM. METHODS: The medical records of 156 consecutive PM/DM patients in 3 medical centers were reviewed. RESULTS: Thirty-six PM/DM patients (23.1%) developed ILD. We observed that 19.4% of patients with ILD had resolution of pulmonary disorders, whereas 25% experienced ILD deterioration. Morbidity and mortality rates were as high as 13.9% and 36.4%, respectively, in PM/DM patients with ILD. Parameters of PM/DM that related to ILD poor outcome were identified as follows: Hamman-Rich-like pattern, initial diffusing capacity of carbon monoxide <45%, neutrophil alveolitis, and histologic usual interstitial pneumonia. Additionally, for the group with ILD, polyarthritis, higher values of erythrocyte sedimentation rate and C-reactive protein, presence of anti-Jo-1 antibody, and characteristic microangiopathy were significantly more frequent. CONCLUSION: Our series underlines the high frequency of ILD in PM/DM patients, resulting in increased morbidity and mortality rates. It also indicates that PM/DM patients should routinely be screened for ILD, even those patients without anti-Jo-1 antibody, because 69% of our ILD patients were seronegative for the anti-Jo-1 antibody. Our findings further suggest that PM/DM patients presenting with factors predictive of ILD poor outcome may require more aggressive therapy.     

Semaphorin 6D regulates the late phase of CD4+ T cell primary immune responses

The semaphorin and plexin family of ligand and receptor proteins provides important axon guidance cues required for development. Recent studies have expanded the role of semaphorins and plexins in the regulation of cardiac, circulatory and immune system function. Within the immune system, semaphorins and plexins regulate cell–cell interactions through a complex network of receptor and ligand pairs. Immune cells at different stages of development often express multiple semaphorins and plexins, leading to multivariate interactions, involving more than one ligand and receptor within each functional group. Because of this complexity, the significance of semaphorin and plexin regulation on individual immune cell types has yet to be fully appreciated. In this work, we examined the regulation of T cells by semaphorin 6D. Both in vitro and in vivo T cell stimulation enhanced semaphorin 6D expression. However, semaphorin 6D was only expressed by a majority of T cells during the late phases of activation. Consequently, the targeted disruption of semaphorin 6D receptor–ligand interactions inhibited T cell proliferation at late but not early phases of activation. This proliferation defect was associated with reduced linker of activated T cells protein phosphorylation, which may reflect semaphorin 6D regulation of c-Abl kinase activity. Semaphorin 6D disruption also inhibited expression of CD127, which is required during the multiphase antigen-presenting cell and T cell interactions leading to selection of long-lived lymphocytes. This work reveals a role for semaphorin 6D as a regulator of the late phase of primary immune responses.     

Endobronchial closure of bronchopleural fistula with Amplatzer PFO device

Bronchopleural fistula (BPF) is a feared postoperative complication of pneumonectomy that carries significant morbidity and mortality. BPF can be treated by various surgical and medical techniques. Endobronchial techniques have been used for the delivery of biological glue, sealants, coils, and covered stents with variable degrees of success, depending on the size of the fistula. A recent case report described the endobronchial closure of a BPF through the implantation of an Amplatzer ASD device, commonly used for transcatheter closure of atrial septal defects. In this case report, we describe closure of a BFP using the Amplatzer PFO device.     

The impact of fibrosis and steatosis on early viral kinetics in HCV genotype 1-infected patients treated with Peg-IFN-alfa-2a and ribavirin

Hepatitis C viral (HCV) kinetics after initiation of interferon-based therapy provide valuable insights for understanding virus pathogenesis, evaluating treatment antiviral effectiveness and predicting treatment outcome. Adverse effects of liver fibrosis and steatosis on sustained virological response have been frequently reported, yet their impacts on the early viral kinetics remain unclear. In this study, associations between histology status and early viral kinetics were assessed in 149 HCV genotype 1-infected patients treated with pegylated interferon alfa-2a and ribavirin (DITTO trial). In multivariate analyses adjusted for critical factors such as IL28B genotype and baseline viral load, presence of significant fibrosis (Ishak stage > 2) was found to independently reduce the odds of achieving an initial reduction (calculated from day 0 to day 4) in HCV RNA of ≥2 logIU/mL (adjusted OR 0.03, P = 0.004) but was not associated with the second-phase slope of viral decline (calculated from day 8 to day 29). On the contrary, presence of liver steatosis was an independent risk factor for not having a rapid second-phase slope, that is, ≥0.3 logIU/mL/week (adjusted OR 0.22, P = 0.012) but was not associated with the first-phase decline. Viral kinetic modelling theory suggests that significant fibrosis primarily impairs the treatment antiviral effectiveness in blocking viral production by infected cells, whereas the presence of steatosis is associated with a lower net loss of infected cells. Further studies will be necessary to identify the biological mechanisms underlain by these findings.     

Differential response to H. pylori eradication therapy of co-existing diffuse large B-cell lymphoma and MALT lymphoma of stomach-significance of tumour cell clonality and BCL10 expression

We recently reported that low-grade mucosa-associated lymphoid tissue lymphoma (MALToma) and diffuse large B-cell lymphoma (DLBCL) with MALToma (DLBCL[MALT]) of stomach are equally responsive to H. pylori eradication therapy (HPET) and that H. pylori-independent status is closely associated with nuclear translocation of BCL10. However, co-existing MALToma and DLBCL components of gastric DLBCL(MALT) may respond differentially to HPET and the underlying mechanism remains unclear. Tumour tissue samples from 18 patients with microdissectable co-existing MALToma and DLBCL cells were studied. The clonality of lymphoma cells was examined by polymerase chain reaction-based amplification of the CDR3 region of the IgH gene and confirmed by DNA sequence analysis. BCL10 expression was determined by immunohistochemistry. Differential response of co-existing MALToma and DLBCL to HPET was defined as complete eradication of one component while the other component remained. Five (27.8%) of the 18 patients showed different IgH gene rearrangements in the two components and three (60%) of these five patients had differential response of MALToma and DLBCL to HPET. By contrast, 13 patients showed identical IgH gene rearrangements and only one (8%) of them had differential response of the two components to HPET (p = 0.044). Further, all four patients with differential response of MALToma and DLBCL to HPET showed nuclear expression of BCL10 in the H. pylori-independent component and cytoplasmic expression of BCL10 in the H. pylori-dependent component while the expression patterns of BCL10 were identical in both of these components in the 14 patients who had similar tumour response to HPET. We conclude that different clonality is a common reason for the differential response of co-existing MALToma and DLBCL of gastric DLBCL(MALT) to HPET and that immunohistochemical examination of BCL10 expression may help to identify the co-existence of these components.     

Morbidity and cost of rotavirus infections in France

BACKGROUND: Rotavirus is the most common cause of severe diarrhea in children. Morbidity and mortality related to rotavirus infection is not well known in temperate countries in general, and in France in particular. OBJECTIVES: The aim of this study was estimate the morbidity, mortality, and cost related to the rotavirus infection in France, in order to assess the potential impact of a vaccination program. METHODS: A birth cohort was followed until 5 years of age using a decision tree model. Rotavirus infection incidence rates were modeled according to age, seasons, and breast-feeding status. RESULTS: Based on estimates from a decision model, we found that in France, rotavirus infection was responsible for 300,000 annual episodes of acute diarrhea, 138,000 visits to general practitioners, 18,000 hospitalizations, and 9 deaths. The annual direct cost related to rotavirus infection care was estimated at 28 million euros. CONCLUSION: This study demonstrates the high morbidity and cost of care associated with rotavirus infection in France. The decision tree model developed in this study could be used in the future to estimate the potential effectiveness, cost and cost-effectiveness of childhood vaccination strategies using new rotavirus vaccines.